Blasting Away

A powerful coronal mass ejection (CME) erupted from the Sun (Jan. 8, 2012). The broad front of the particle cloud had already expanded to about 120 degrees when this image was taken. Here the Sun itself has been enlarged about 50% and superimposed on the background image to cover the coronagraph's occulting disk. The occulting disk blocks out the Sun's bright light so that the fainter structures in the corona can be observed. CME's carry a billion tons of matter into space at over a million miles per hour. Both images are from the STEREO (Ahead) spacecraft.